I moved some push buttons around a time or two. As noted, this is just adding wires to a switch that's already there. It's N/O (Normally Open) and any closer along the line will act the same way. Run the two wires down the street, mount it to a stop sign, and the local kids can restart the machine...for what it's worth anyway.
I did this kind of thing, kinda, with how I want my CD drives to eject. You just tie in to the stuff that's already there and move the switch where you want it.
You're right though, that's tough on a machine to just hard reset it! I play games at work, and if someone was actually around and I cared, I'd be looking for something too. There's methods to do something with the same effect with software though. I'm not writing any, but there's some out there. Does Alt-Tab work and is fast enough to hide what you're doing? I'd think it'd be less obvious than walking up to you and always seeing your computer rebooting. If I were a boss, I'd probably just call IT after seeing that a couple times...or be really curious.
But I know there's some panic ware out there with hotkeys that are safer than killing the computer every time the boss comes up (Wife, same thing) and requires nothing to wire up.